This invention relates to a peritoneal catheter device for dialysis or the like treatments in the abdominal cavity.
Peritoneal dialysis is performed by implanting into the peritoneal, or abdominal cavity, a peritoneal dialysis catheter. The catheter may be connected via a tube to a dialysis port. The dialysis port can be positioned interior or exterior to the patient's body, as shown in U.S. Pat. No. 5,090,954, issued to Geary, the inventor herein. Dialysis fluid may be injected into the dialysis port or the external portion of the catheter, which then travels to the catheter through a connecting conduit, and thereby out the catheter into the peritoneal cavity. Once in the peritoneal cavity the dialysis fluid bathes the peritoneal surfaces within the cavity, whereby the chemical and physical interactions of dialysis take place. After the exchange of fluids, suction is applied to the connecting conduit which pulls the dialysis fluid, containing the exchanged impurities, out of the peritoneal through the catheter, ending the dialysis procedure.
In response to the object of increasing a catheter's outer surface area, prior art devices with large surface areas were developed. In particular, U.S. Pat. No. 4,437,856, issued to Valli, discloses a peritoneal catheter device for dialysis with an expandable outer surface. FIG. 2 of Valli discloses a catheter 1 having an inflatable membrane 11 which surrounds a single inner catheter 2. Inflation of the balloon shaped outer membrane 11 increases the effective fluid contact surface area of the inner catheter 2, thereby increasing the effectiveness of the dialysis procedure. As shown in Valli at FIG. 2, outer membrane 11 has round holes 11' to allow passage of the dialysing liquid from the inner catheter 2 to the outer surface of membrane 11.
One of the major problems associated with current peritoneal dialysis is poor flow through the catheter into the peritoneal. Most of the time, this is due to particulate matter trapped within and around the catheter which blocks holes in the catheter through which the fluid flows. The particulate matter is often formed of protein in the form of fibrin, which readily adheres to current catheters and the holes therein. Another source of catheter blockage is the greater omentum, a large apron of fatty tissue that serves to insulate inflammation or other foreign objects within the peritoneal cavity. The omentum often becomes adhered to the catheter, occluding the fluid channels. Yet another problem is the bowel and the intestines, which become entangled with the free floating intraperitoneal catheters currently used. Still other sources of particulate matter are the organs themselves, protein globules and tissue pieces broken off the omentum.
Balloon shaped catheters, as disclosed in Valli, often become entangled with the omentum, bowel, intestines or other organs. In addition, catheters with round holes for the passage of dialysis fluid, as shown in Valli, become clogged because particulate matter and protein in the form of fibrin readily adheres to such round holes.
The catheter of this invention overcomes these problems with the prior art by having a large surface area for fluid exchange, and a generally flat, elongate outer shape, so that the catheter may be placed against the peritoneal wall, avoiding the problem of entanglement with the omentum, bowel, intestines and other organs. In addition, the present invention overcomes the problem of fluid passageway occlusion by disclosing a design which inhibits occlusion by particulate matter. This is accomplished by incorporating a system of multitubing channels sandwiched between a non-adherent outer surface that discourages tissue or fibrin adherence. In addition, the outer surface has coaptable slits, instead of round holes, to further discourage tissue or fibrin adherence.
A design limitation of peritoneal catheters is that they must be compact in shape to fit comfortably in the patient's peritoneal cavity. In addition, flexible catheters that can be compacted to fit within a tube can be positioned in the peritoneal by laproscopy placement, a minimally intrusive surgical procedure.
In view of the problems with the prior art outlined hereinabove, an object of the present invention is to provide a novel catheter device which has a large outer surface area to promote effective fluid exchange.
A further object of the invention is to provide a catheter with a generally flat design so that the catheter can be placed adjacent the peritoneal cavity wall, avoiding entanglement with the omentum, bowel, intestines, or other objects within the peritoneal cavity, yet still provide a large surface area for fluid exchange.
A further object of the invention is to provide a catheter device in which the design inhibits occlusion of the fluid passageways, such as by incorporating slit shaped holes.
A further object of the invention is to provide a flexible catheter which can be compacted such that it may be inserted into the peritoneal cavity by the method of laproscopy placement.